The ingredients of coffee can be divided into the following

Caffeine: it has a particularly strong bitter taste and stimulates the central nervous system, heart and respiratory system. The right amount of caffeine can reduce muscle fatigue and promote digestive juice secretion. It also promotes kidney function, has a diuretic effect, and helps the body expel excess sodium ions from the body, but eating too much can lead to caffeine poisoning.

Tannic acid: the boiled tannic acid will decompose into pyrouric acid, so the coffee that has been brewed for too long will taste worse.

Fat: the most important ones are acid fat and volatile fat.

Acidic fat: fat contains acid, its strength will vary according to the type of coffee.

Volatile fat: is the main source of coffee aroma, it is a kind of aroma will emit about 40 kinds of aromatic substances.

Protein: the main source of calories, the proportion is not high. Most of the protein in coffee beans will not dissolve out when brewing coffee, so the intake is limited.

Sugar: coffee beans contain about 8% sugar. After baking, most of the sugars are converted to caramel, which browns the coffee and combines with tannins to produce sweetness.

Fiber: the fiber of raw beans will be carbonized after baking and combine with caramel to form the hue of coffee.

Minerals: contains a small amount of lime, iron, phosphorus, sodium carbonate and so on.

Coffee nutrients: per 100 grams of coffee beans contain 2.2 grams of moisture, 12.6 grams of protein, 16 grams of fat, 46.7 grams of sugar, 9 grams of cellulose, 4.2 grams of ash, 120 milligrams of calcium, 170 milligrams of phosphorus, 42 milligrams of iron, 3 milligrams of sodium, 0.12 grams of vitamin B2, 3.5 milligrams of nicotinic acid, 1.3 grams of caffeine and 8 grams of tannins. Every 100 grams of coffee extract contains 99.5 grams of water, 0.2 grams of protein, 0.1 grams of fat, 0.1 grams of ash, trace sugars, 3 mg of calcium, 4 mg of phosphorus, 2 mg of sodium, 0.01 mg of vitamin B2 and 0.3 mg of nicotinic acid. Dissolve 10 grams of coffee in hot water with 0.04 grams of caffeine and 0.06 grams of tannins.